A more thorough explanation:

Term: ad hominem
Definition: Ad hominem means attacking someone's character instead of their argument. It's like name-calling instead of using facts and logic to make your point. For example, if someone says that smoking is bad for your health, and someone else responds by saying "well, you're just a hypocrite because you eat junk food," that's an ad hominem attack. It doesn't address the argument about smoking, it just tries to discredit the person making the argument. Ad hominem attacks are not a good way to have a productive conversation or debate.